a) Field of the Invention
This invention relates to a method for testing the intactness of stored data in a processing facility for sheet material such as bank notes or papers of value.
b) Discussion of Related Technology
Such a processing facility is generally constructed of several components. Each of these components fulfills certain functions in processing the sheet material. One component of the processing facility is a control device which ranks higher than the other components. The control device controls the individual operations of the processing facility. The other components are designed as modules which perform the actual processing of the sheet material. Possible processing operations of individual modules are e.g. singling the sheet material from a stack, testing the sheet material for state or authenticity, transporting the sheet material, stacking or destroying the sheet material.
The processing facility components can be provided with memories for storing data necessary for operating the processing facility. These data can be for example control commands, programs, result data or reference data. The individual components of the processing facility are interconnected in such a way that data can be transferred between them.
The processing facility can be operated in different operating states. The operating states can be fixed for example by the operator inputting certain parameters. Such parameters can be the number of sheets to be tested, the denomination of bank notes, the type or quality of certain test criteria or similar information.
DE-PS 27 60 453 discloses such a processing facility. For storing data both the control device and individual modules have their own memories for storing data necessary for operating the processing facility. The data exchange between the control device and the modules is performed via a main memory which both the modules and the control device can access. In addition the modules are directly interconnected for data exchange.
DE-OS 33 47 607 shows a processing facility wherein a plurality of similar modules are used for optically testing the sheet material. Both the control device and the individual modules have their own memories for storing data. The individual modules are connected with one another and with the control device via a data bus. A higher-order memory which all components of the processing facility can access is additionally connected to the data bus.
In apparatus of the stated type undesirable changes can generally occur in the data stored in the processing facility. These changes can arise either from disturbances in the processing facility, such as data transmission errors or data loss, or from deliberate manipulation of the data with intent to defraud.
Known apparatus are provided with no measures for ascertaining undesirable changes in the data stored in the processing facility.
On these premises the invention is based on the problem of proposing a method for testing the intactness of data stored in a processing facility for sheet material to permit ascertainment of changes in said data.